The invention relates to couplings in general, and more particularly to improvements in couplings for separably and fluidtightly connecting an end portion of a first tubular component (such as a nipple at one end of a metallic or plastic pipe) with an end portion of a second tubular component (e.g., a flexible elastic hose). Still more particularly, the invention relates to improvements in couplings of the type wherein a sleeve-like tubular coupling member is at least partially insertable into the end portion of the second component and has one or more prong-like elastically deformable coupling elements engageable with an external retainer of the end portion of the first component, wherein at least one annular sealing element is interposed between the exterior of the end portion of the first component and the sleeve, and wherein an annular clamping member serves to maintain the end portion of the second component in sealing engagement with the exterior of the sleeve.
Commonly owned U.S. Pat. No. 4,775,173 to Sauer discloses a hose coupling wherein the sleeve is provided with an external groove for reception of a sealing element which is confined in the end portion of one of the two tubular components in assembled condition of the coupling. The sleeve extends into the end portions of both tubular components and is provided with elastically deformable external prongs which can engage an external retainer on one of the end portions. The sleeve is made of a plastic material.
A drawback of the patented coupling is that the sleeve is rather expensive because it must be produced in a complex plastic processing machine. Moreover, the radially outwardly extending prong-like coupling elements of the sleeve are likely to be accidentally disengaged from the retainer or damaged in storage, during shipment or in actual use of the coupling. Still further, a substantial force must be exerted for introduction of the sleeve into the end portion of the one and/or the other tubular component.